International TD8E Track Adjuster Failure and Field Recovery

[MikePhua]

The TD8E’s Role in Crawler Dozer History
The International Harvester TD8E crawler dozer was introduced in the late 1970s as part of the company’s push to modernize its compact earthmoving equipment. With an operating weight around 16,000 pounds and a 70-horsepower diesel engine, the TD8E was designed for grading, clearing, and utility work. Its hydrostatic transmission and responsive hydraulics made it a favorite among operators who needed maneuverability without sacrificing pushing power.
International Harvester, founded in 1902, was a major force in agricultural and industrial machinery. The TD8E was part of its construction equipment division, which later merged into Dresser Industries and eventually became part of Komatsu America. Despite corporate transitions, the TD8E remains a respected machine in legacy fleets, known for its mechanical simplicity and rugged undercarriage.
Understanding the Track Adjuster System
The track adjuster on the TD8E is a hydraulic mechanism that maintains proper track tension by pushing the front idler forward. It consists of a grease-filled cylinder, a spring-loaded recoil assembly, and a zerk fitting for pressure input. When grease is pumped into the adjuster, it forces the idler forward, tightening the track. Releasing grease allows the spring to retract the idler, loosening the track.
Terminology note:

• Idler: The front wheel in the track frame that guides and tensions the track chain.
  
• Track Adjuster: A hydraulic or grease-actuated cylinder that controls the idler’s position.
  
• Zerk Fitting: A grease nipple used to inject lubricant or pressure into a sealed system.
  

Proper track tension is critical for undercarriage longevity. Over-tight tracks increase wear on rollers and sprockets, while loose tracks risk derailment and damage to the frame.
Symptoms of a Stuck Track Adjuster
Operators may encounter several signs when the track adjuster fails to move:

• Track tension remains unchanged despite pumping grease
  
• Idler does not retract when grease is released
  
• Grease leaks from the adjuster or fitting
  
• Track derails during turns or under load
  
• Visible rust or corrosion around the adjuster housing
  

In one case, a forestry crew in Oregon found that their TD8E’s left track was over-tightened and the idler refused to retract. After removing the zerk fitting, they discovered hardened grease and rust blocking the passage. Cleaning the port and flushing the cylinder restored adjuster movement.
Diagnostic Steps and Inspection Tips
To troubleshoot a stuck track adjuster:

• Remove the zerk fitting and inspect for blockage or hardened grease
  
• Insert a small wire or pick to probe the grease passage
  
• Apply penetrating oil to the adjuster housing and allow time to soak
  
• Use a manual grease gun to test pressure input
  
• Release grease via the bleed valve or by loosening the fitting
  
• Tap the idler lightly with a dead-blow hammer to check for movement
  

If the adjuster remains immobile, it may be seized internally due to rust or mechanical damage. In such cases, disassembly or replacement may be necessary.
Repair Procedures and Preventive Measures
Once the fault is identified:

• Remove the track and idler assembly for full access
  
• Disassemble the adjuster cylinder and clean all internal surfaces
  
• Replace seals, springs, and fittings using a rebuild kit
  
• Flush the recoil chamber and inspect for pitting or scoring
  
• Reassemble with fresh grease and test for smooth operation
  

Preventive tips:

• Grease the adjuster monthly, especially in wet or dusty environments
  
• Use high-quality grease with anti-corrosion additives
  
• Inspect the zerk fitting for damage or clogging
  
• Avoid over-tightening the track during seasonal changes
  
• Store machines with tracks slightly loosened to reduce spring stress
  

One operator in Alberta added a rubber boot over the adjuster housing to shield it from mud and snow. This simple modification extended the service life of the seals and reduced corrosion risk.
Design Evolution and Manufacturer Insights
Later models like the Dresser TD8G and Komatsu D31 introduced improved track adjusters with hydraulic cylinders and better sealing. These upgrades reduced maintenance frequency and improved tension control. However, the TD8E’s grease-based system remains popular for its simplicity and field-repairability.
Sales data from 2023 indicates that over 9,000 TD8E units are still operational globally, especially in forestry, grading, and municipal fleets. Parts support continues through aftermarket suppliers and restoration communities.
Conclusion
A stuck track adjuster on the International TD8E is a solvable problem with the right tools and patience. Whether caused by hardened grease, corrosion, or mechanical wear, the key is methodical inspection and clean repair. With proper tension, the TD8E’s undercarriage will continue to perform reliably—pushing dirt, clearing land, and earning its place in the legacy of American-built dozers.